Cell phones are a particularly easy way to rack up expensive charges very quickly, as the caller is essentially billed by two companies. MTN sets up a mini-cell tower on the ship and charges for the transmission that takes your voice and sends it to the satellite and back down to land. In addition, your cell phone provider (AT&T, Verizon, etc.) also charges a roaming rate. While you don't see a separate line in your bill from MTN, rest assured it is getting a cut.

If you're looking to minimize costs, beware of incoming text messages. Keep your cell phone off -- or in airplane mode -- to prevent these charges, and don't use the mobile network provided by the ship to download messages. Data costs while roaming on a mobile network can be very heavy, so if you didn't bring your laptop and want to use your phone to surf or check messages, you are better off using the ship's Wi-Fi service. (Just turn off your phone's ability to access mobile signals, but keep the Wi-Fi ability active.) The rate is the same whether using a laptop or a cell phone, and those that want to quickly check messages need only log on for the few minutes it takes to download messages before signing off. Those who want to surf are still better off since they are not being charged for both data and minutes while roaming.

The best bet for smartphone users, however, is to find that free Wi-Fi hotspot ashore -- and download all your e-mails at no charge. Your fastest connection will always be onshore, and for those who simply want to check that all is well at home, using free Wi-Fi in port with your smartphone is best. I've managed to find free Wi-Fi ashore in the Caribbean near the pier in almost every port. Local tourism offices (or even the ship's crew, who seem to know all the hotspots in the ports they frequent) can be very helpful in pointing out where you can quickly connect and check your messages at your convenience. If you call from shore, you will be charged at whatever the port’s international rate is for your cell phone plan. If you call from sea, the rate will be much higher, although not as high as if you had used a ship phone.Phone Cards If the ship is at sea and you need to make an urgent call home, you can still minimize the expense somewhat if you have a cruise ship phone card. You’ll have to plan ahead and do research about the cards available. Compare rates and look for maintenance fees. You’ll also need to make your purchase before you take your cruise.Ship Internet Communicating via the Internet on a cruise ship can be tricky and expensive. Most cruise ships have at least a cybercafé where you can connect to the Internet even while at sea. Some ships even have wireless access so you can connect from the comfort of your room. If you are going to use email for communication, you may want to use a Web-based email address. It will simplify your communications. Otherwise, you may need to know your server settings to configure your computer to access your e-mail from the cruise ship. This can still be a very expensive method of communicating, so you don’t want to spend a lot of time surfing the Internet. Another useful tip is to simply write your e-mail in a Word program or an offline version of your e-mail provider, and then paste what you've written into an e-mail (or hit send) as soon as you log in. It's best to have your own laptop if you want to take this approach, as many onboard computer terminals have been re-jiggered so you cannot access basic word processing programs like Microsoft Word or Notepad. This won't change your connection speed, but it may save you money and give you a better chance of actually getting your e-mail sent. Fees on Carnival ships include: Internet access at the cyber cafe or on personal laptops costs 75 cents per minute. Also, minutes can be bought in blocks: 480 minutes for $159; 240 minutes for $89; 120 minutes for $59; 45 minutes for $29. There is also a one-time activation fee of $3.95. A limited number of laptops are available for rent on all Carnival ships for a fee ($9 to $10 a day); they're complimentary with the purchase of an Internet package.Port Cybercafes If you do want to use the Internet, the best thing to do is to wait until you reach a port and then find a cybercafé. You will pay only a fraction of what you would need to pay to access the Internet while aboard the ship. Ask at the purser’s desk for directions to the nearest one at a port or visit a tourist information office ashore.Walkie-Talkies If you’re on a family excursion and want to keep track of your kids while they are on board doing youth activities, consider using a two-way radio or walkie-talkie to communicate. These are easy to carry and cost you nothing to use. It is the best way to communicate with someone else on your ship.Ship Phone Whatever you do, don’t use the ship’s phone to communicate with anyone off your ship. You will be shocked with how expensive the cost will be even if someone is calling onto the boat to talk to you. This should be your communication method of last resort.